iMX6 IPU DC

[ogj]

In the SDK ipu ipu_dc_write_channel_config function, one of the things that is written is the DC_WR_CH_CONF_5 register. The field  PROG_DISP_ID_5 is set to 2. What does this value mean? What are the 4 options? The manual states display #0, display #1, display #2, display #3 with no more explanation.

[ogj]

The reason I ask this question is because in the SDK file "ipu_common.h" there is the declaration:

enum disp_port {
IPU1_DI0,
IPU1_DI1,
IPU2_DI0,
IPU2_DI1,
};

So if  PROG_DISP_ID_5 is set to 2, that would indicate that the output is on IPU2 DI0, and I'm pretty sure it comes out of IPU1 DI0.

The code is:

In the function ipu_dc_config:

      uint32_t disp_port = 2; //up to 4 display is supported by one IPU.

      ipu_dc_display_config(ipu_index, disp_port, 2, 0, width - 1);

In the function ipu_dc_display_config:

      ipu_write_field(ipu_index, IPU_DC_WR_CH_CONF_5__PROG_DISP_ID_5, disp_port);

[joanxie]

what's your demands? do you want to enable IPU2 DI0, but you get the video from IPU1 DI0?  refer to the Reference Manual,When channel 28 is connected to DI0, channel 23 must be connected to DI1 even if ch23 is not used. This is done by programming the PROG_DISP_ID_5 field, so you need to check the channel status,  in fact, you don't need to change these registers, just use the default settings in the bsp, if you need to change the IPU1 DI0 to the IPU2 DI0, just refer to the dts file, to check if you set your display to the IPU2 DI0, otherwise you couldn't get video from it

[ogj]

I not using IPU2 and I'm not using channel 28. I'll just be using IPU1 DI0 and channels 23 and 27, and combining them in the DC. My point is that in the DC_WR_CONF_5 register, the explanation for the PROG_DI_ID_5 field is:

What are the definitions of display #0-3? There is no further explanation anywhere in the RM. Am I supposed to just pick a number and see where the data comes out? There are lots of holes in the documentation for the IPU. Some of the explanations can be gleaned from the SDK, but much can't. I am not using linux so there isn't any dts. I'm just trying to figure out how things work using the SDK code.

[joanxie]

display# is display streaming, irrelevant to DI, like overlay, backgroud